Stoker



June 2; 1942. 's. VAN ETTEN 2,285,236

STOKER Filed Aug. 1, i940 lnventor Scott Win, L'Z'terp (Ittomeg Patented June 2, .1942

UNITED STATES PATENT OFFICE STOKER I Scott Van Etten, Columbus, Ohio Application August 1, 1940, Serial No. 349,177

1 Claim.

This invention relates to mechanical stokers. In such stokers, it is desirable that the coal supplied be suitably fine in order that it shall be readily combustible at the burner. Coal of the bituminous variety often comes in lumps of not freely burnable size mixed with dust, the latter herein shown and described, the feature of novelty being pointed out in the claim.

In the accompanying drawing- Figure 1 is mainly a viewin side elevation broken outto show details.

Fig. 2 is a top plan view.

Fig. 3 is an elevation viewed from the right hand side of Fig. 1.

Fig. 4 is a vertical section on the line IVIV, Fig. 1.

Fig. 5 is a face view of the rotary crusher; and

Fig. 6 is an edge view of the same.

In the views, the character l0 designates the hopper which generally, is in the form of a box of sheet metal having a cover ll hinged at [2 to the top of the hopper. The said hopper has generally speaking a tapered V-shaped bottom portion shown as terminating in a trough I3 that leads into one end of a fuel delivery pipe i4 having at its other end a burner l5. In the said trough and feed pipe is a feed worm I6 operated by suitable power to cooperate in moving the fuel from the hopper to the burner.

Secured at a suitable slant in the hopper is a screen or grid I'l including a series of parallel bars suitably spaced for the purpose of appropriately separating or screening the coal that is thrown onto it into large and small portions. It will be observed that said screen II extends slantingly downward from the rear wall of the hopper above the feed worm 16 to the forward portion of the hopper to the crushing burs so that most of the fine fuel falls into the feed trough in advance of the fractured lumps of fuel.

Arranged in the lower or tapered portion of the hopper is a pair of suitable burs or crushing rolls l8 and I! as shown in Fig. 1. The burs or roll l8 are preferably fixed so that its bevel rim is flush with the incline of the screen while the cooperating roll I9 is journaled and provided with any suitable and obvious electric motor 20 protected by a hood and gearing for rotating it. The axis of the burs is substantially parallel to the axis of the feed worm l6.

Operated by the same power that operates the crushing roll I9 is a fan blower 22 for supplying air through a pipe to the burner. Connected with the burner is a return pipe 24 employed as a clean out.

In practice when. the coal is thrown onto the screen, the dust and smaller portions drop into the trough at the bottom of the hopper while the larger pieces are pulverized by the crushing rolls also fall into said trough, and both portions are fed from the trough by the feed worm to the feed pipe leading to the burner.

The forms and dimensions of the parts can be i changed without departing from the gist of the invention as claimed.

What I claim is:

A coal stoker including, in combination, a hopper having a V-shaped portion formed as a trough at its bottom extended from front to rear of the hopper, a coal feeding worm in said. trough and means for rotating the same, a coal screen in said hopper above said feed worm extending slantingly downward from the rear portion of the hopper over said trough and above the rearwardly coal feeding portion of said feed worm to discharge. coal dust and small particles into said trough and onto the rear portion of said feed worm, and a pair of cooperating fuel fracturing burs in said hopper at the base of said screen, one of which burs has its axis of rotation parallel to the axis of rotation of the said feed worm.

SCOTT VAN ETTEN. 

